[Questions from students] What are the general requirements for electric construction machinery and hand-held power tools? 1. In the construction site, the purchase, use, inspection and maintenance of electric construction machinery and hand-held electric tools shall comply with the following provisions: 1) The purchased electric construction machinery, hand-held electric power tools and electric safety devices shall comply with the relevant national mandatory standards, and shall have the product qualification certificate and operation manual; 2) Establish and implement the system of special person and special plane responsibility, and regularly check and maintain; 3) The ground shall meet the requirements, and there shall be no less than 2 connection points between the metal base and shell of the equipment that generates vibration during operation and PE line; 4) Leakage protection meets the requirements; 5) Use, inspect and maintain according to the instructions. 2. The metal operating platform of tower crane, external elevator, slide lift template and the material hoist with lightning protection device shall be connected with PE wire and shall also be grounded repeatedly. Electrical connections shall be ensured between metal structural members of the equipment.